any experiences spraying mohawk sealer?

[mistermikev]

so... admittedly this was my first time spraying anything with my compressor... and perhaps this is not the right product...

I bought some mohawk vinyl sealer as it was recommended to me somewhere to work with mohawk nitro lacquer (looking back this seems like an odd combo).  I sprayed my two bodies last weekend but out came all these fine hairs and other particulate.  I figured i just needed to add a filter to my compressor... so added a spray filter right at the gun and an inline filter 15' back on a line.  sm issue!

I got enough sealer on that it was fine, and I spent the time and cleaned/sanded the bodies.  Then sprayed nitro clear just to see if I'd have the sm issue... no issue whatsoever.  

Now I'm left scratching my head... it could be that since the sealer sprays sort of opaque... perhaps it just magnifies any debris?  Perhaps I sprayed out all the crap (I did clean the gun with some acetone between sealer and clear).  what is your guess?

I'm afraid to ever use this sealer again because it was such a pain to clean.  Would love to hear any/all experiences with it!

[mistermikev]

well for the record... I think I may have answered my own question last night while I was cleaning up one of these bodies.  I noticed the highest concentration of 'stuff' was in the f holes so wondering if perhaps this was all just sitting in there and got blown out when I sprayed.  I guess i'll have confirmation the next time I use this sealer.

[ScottR]

I've used the Behlen vinyl sealer without any issues, and Behlen and Mohawk are the same company, same thing.

I'd say your investigation probably gave you the correct answer. I don't use sealer anymore though, actually besides testing it a couple of times I really never used it. Thinned lacquer does the same thing and better in my opinion. And since I've gone back to CA for pore filling, there is no need for even that. CA seals very effectively, albeit it messy and can be a pain to level.

@Drak usually has very good information about sealing steps.

SR

[mistermikev]

6 hours ago, ScottR said:

I've used the Behlen vinyl sealer without any issues, and Behlen and Mohawk are the same company, same thing.

I'd say your investigation probably gave you the correct answer. I don't use sealer anymore though, actually besides testing it a couple of times I really never used it. Thinned lacquer does the same thing and better in my opinion. And since I've gone back to CA for pore filling, there is no need for even that. CA seals very effectively, albeit it messy and can be a pain to level.

@Drak usually has very good information about sealing steps.

SR

thank you for the reply.  I have not used sealer before but I wanted to give it a try as I've read that it can limit the amount of shrinkage you get from nitro.  I guess time will tell how much impact that has, but I was hoping someone would mention that and bolster what I've read.   

[mistermikev]

so just wanted to update in case anyone else ever has this similar issue.  I had it again when I was spraying lacquer and never would have guessed this was not debris.  Was hunting around on sites trying to find keywords that would bring me to someone with the sm issue... and finally found this thread that describes EXACTLY what my issue is:

'sounds like improper reduction of material shot at high pressure. In the good old days this was known as "spider webbing", or "Cobwebbing", done with old lacquer type finishes.
Clean gun and reduce the material to proper ratio to finish, shot at correct pressure for gun and material in use.

the stuff actually looks like little airborne debri that might have been shot with lacquer.  Kind of looks like little feathers or hairs that end up on the finish.  "spider webbing" describes it pretty good too.  Admittedly... have not figured out how to dial in either gun I have... but this puts me on the path.  Gun is clean as a whistle... but lacquer was not reduced at all, and now that they mention it... I think my pressure was a bit high!  anywho

[RaleighBG]

So glad you found the info on cobwebs. Its the Bain of a nitro finisher's existence and will flat out ruin a nice job. The Vinyl sealer is the absolute RIGHT thing to use first before shooting nitro. It is itself a nitro cellulose lacquer with some vinyl solids added in. It seals the wood and gives the subsequent coats of nitro a familiar surface to stick to. But remember it sits on the surface it doesn't really penetrate. I've found it also is the place to start a nice transparent color as well. It's fully tint compatible, so your transients or mixologist pigments can go right in. Just don't sand the wood too high or it will chip easy, and when it chips it will go all the way to natural wood. There's a million ways to skin a cat with finishing but I'd stick to the vinyl. If you run into a challenge where cutting the pressure to avoid cobwebs isn't enough pressure to move the material just thin it a tad. I use an HVLP gun and turbine from Apollo and it still cobwebs real easy. I usually have to go real thin coats at first with the vinyl. A little secret with the Belen's/Mohawk.... They make a secret sauce that the big brand custom shops use as a secret weapon. It's confusingly called Piano Lacquer. It's a special high build formulation of the same nitro finish as Classic Instrument Lacer you are likely already using, but it's designed to shoot thicker coats without the off gassing bubbles. If your looking for a DEEEEEEP THICK glass finish its just what the doctor ordered. I use JUST Piano Lacquer, but you could use it as your final clear coats instead. I can shoot a finish that looks like 10-12 coats in just 3-4.